Merge lp:~alan-griffiths/miral/revised-resize into lp:miral

[Alan Griffiths]

Update the resize logic in CanonicalWindowManagerPolicy following the discussion on lp:1447886

Update the resize logic in CanonicalWindowManagerPolicy following the discussion on lp:1447886

It now looks at the gesture as a whole and only does position checking at the start of the resize gesture. Thereafter the gesture continues until the button is released, regardless of whether the cursor is still inside the surface/titlebar.

[Cemil Azizoglu (cemil-azizoglu)]

Looks good

review: Approve

[lp:~alan-griffiths/miral/revised-resize]

165. By Alan Griffiths on 2016-04-28

Tweak after trying backport to Mir

=== modified file 'miral-shell/canonical_window_manager.cpp'
--- miral-shell/canonical_window_manager.cpp	2016-04-22 09:06:25 +0000
+++ miral-shell/canonical_window_manager.cpp	2016-04-28 09:25:50 +0000
@@ -83,10 +83,11 @@
     }
 }
 
-void CanonicalWindowManagerPolicy::resize(Point cursor)
+bool CanonicalWindowManagerPolicy::resize(Point cursor)
 {
-    select_active_window(tools->window_at(old_cursor));
-    resize(active_window(), cursor, old_cursor);
+    if (!resizing)
+        select_active_window(tools->window_at(old_cursor));
+    return resize(active_window(), cursor, old_cursor);
 }
 
 
@@ -653,6 +654,7 @@
         mir_pointer_event_axis_value(event, mir_pointer_axis_y)};
 
     bool consumes_event = false;
+    bool resize_event = false;
 
     if (action == mir_pointer_action_button_down)
     {
@@ -669,7 +671,7 @@
 
         if (mir_pointer_event_button_state(event, mir_pointer_button_tertiary))
         {
-            resize(cursor);
+            resize_event = resize(cursor);
             consumes_event = true;
         }
     }
@@ -692,6 +694,7 @@
         }
     }
 
+    resizing = resize_event;
     old_cursor = cursor;
     return consumes_event;
 }
@@ -782,39 +785,62 @@
 
 bool CanonicalWindowManagerPolicy::resize(Window const& window, Point cursor, Point old_cursor)
 {
-    if (!window || !window.input_area_contains(old_cursor))
+    if (!window)
         return false;
 
+    auto& window_info = tools->info_for(window);
+
     auto const top_left = window.top_left();
     Rectangle const old_pos{top_left, window.size()};
 
-    auto anchor = top_left;
-
-    for (auto const& corner : {
-        old_pos.top_right(),
-        old_pos.bottom_left(),
-        old_pos.bottom_right()})
+    if (!resizing)
     {
-        if ((old_cursor - anchor).length_squared() <
-            (old_cursor - corner).length_squared())
+        auto anchor = old_pos.bottom_right();
+
+        for (auto const& corner : {
+            old_pos.top_right(),
+            old_pos.bottom_left(),
+            top_left})
         {
-            anchor = corner;
+            if ((old_cursor - anchor).length_squared() <
+                (old_cursor - corner).length_squared())
+            {
+                anchor = corner;
+            }
         }
+
+        left_resize = anchor.x != top_left.x;
+        top_resize  = anchor.y != top_left.y;
     }
 
-    bool const left_resize = anchor.x != top_left.x;
-    bool const top_resize  = anchor.y != top_left.y;
     int const x_sign = left_resize? -1 : 1;
     int const y_sign = top_resize?  -1 : 1;
 
-    auto const delta = cursor-old_cursor;
-
-    Size new_size{old_pos.size.width + x_sign*delta.dx, old_pos.size.height + y_sign*delta.dy};
-
+    auto delta = cursor-old_cursor;
+
+    auto new_width = old_pos.size.width + x_sign * delta.dx;
+    auto new_height = old_pos.size.height + y_sign * delta.dy;
+
+    auto const min_width  = std::max(window_info.min_width, Width{5});
+    auto const min_height = std::max(window_info.min_height, Height{5});
+
+    if (new_width < min_width)
+    {
+        new_width = min_width;
+        if (delta.dx > DeltaX{0})
+            delta.dx = DeltaX{0};
+    }
+
+    if (new_height < min_height)
+    {
+        new_height = min_height;
+        if (delta.dy > DeltaY{0})
+            delta.dy = DeltaY{0};
+    }
+    
+    Size new_size{new_width, new_height};
     Point new_pos = top_left + left_resize*delta.dx + top_resize*delta.dy;
 
-    auto& window_info = tools->info_for(window);
-
     apply_resize(window_info, new_pos, new_size);
 
     return true;
 
=== modified file 'miral-shell/canonical_window_manager.h'
--- miral-shell/canonical_window_manager.h	2016-04-22 09:06:25 +0000
+++ miral-shell/canonical_window_manager.h	2016-04-28 09:25:50 +0000
@@ -88,7 +88,7 @@
 
     void drag(Point cursor);
     void click(Point cursor);
-    void resize(Point cursor);
+    bool resize(Point cursor);
     void toggle(MirSurfaceState state);
 
     auto active_window() const -> miral::Window;
@@ -108,6 +108,10 @@
     using FullscreenSurfaces = std::set<miral::Window>;
 
     FullscreenSurfaces fullscreen_surfaces;
+
+    bool resizing = false;
+    bool left_resize = false;
+    bool top_resize  = false;
 };
 
 #endif /* MIRAL_SHELL_CANONICAL_WINDOW_MANAGER_H_ */